In eastern India, a two-day strike called by Maoist rebels to protest a government plan to establish special industrial parks on farmland has hit public transportation. As Anjana Pasricha reports from New Delhi, the strike could mark a change of tactics for the rebels.

Police say Maoist rebels blew up rail tracks, attacked two freight trains and set ablaze several trucks Tuesday in three eastern Indian states at the start of a 48-hour economic blockade.

Authorities say rail traffic and bus services were disrupted in some places in Jharkhand, Bihar, and Chattisgarh following the sporadic violence.

The rebels called the strike to protest a recent government decision to allow industries to establish special economic zones. The government is hoping these enclaves will attract investors and boost employment.

But the rebels say the special economic zones or SEZ's will displace tens of thousands of villagers.

The Maoists are not the first to raise their voice against the enclaves. The proposal has already sparked protests from farmers who will lose their land.

The head of New Delhi's independent Institute of Conflict Management, Ajay Sahni, says the blockade is a new tactic by the Maoist insurgents, who have been blamed for mounting attacks on police and security posts in recent years.

"This, I think, would be the first coordinated blockade over an extended area on an issue of this nature…this is the beginning of a new trend," Sahni said. "It represents a very serious threat to the continuity of economic activities over wide areas…I am not merely talking about proposed SEZ's. I am talking about industrial projects that are already partially underway, others that are already operational."

Authorities say they have stepped up security in what they called "vulnerable areas."

In recent years, attacks by the Maoist rebels have escalated, and their influence has gradually spread across a wide belt of eastern and central India.

Security agencies say the rebels now have a presence in nearly half of India's 29 states.

Prime Minister Manmohan Singh has described the communist rebels as the biggest threat to India's internal security and has urged state governments to do more to combat their growing influence.

But security experts say the rebels continue to make steady inroads in rural areas that remain untouched by India's economic boom. The insurgents say they are fighting for the rights of poor peasants and landless workers.